JP7202464B2 - Repair laser welding method and repair laser welding apparatus - Google Patents

Description

For example, the present disclosure includes a deck plate (one of the materials to be welded) that constitutes a steel deck that supports a pavement portion of a bridge, and a U-rib that is joined to the surface of the deck plate by fillet welding (the other The present invention relates to a repair laser welding method and a repair laser welding apparatus used for repairing cracks occurring in joints with welded materials).

For example, in the steel floor slab described above, the side edges of the U-ribs joined to the surface of the deck plate by fillet welding are joined obliquely to the deck plate. At this time, although unwelded portions remain in the root portion of the joint portion between the side edges of the deck plate and the U-rib, the depth of penetration of the welded portion is set to clear a predetermined specified value, resulting in strength. is ensured.

However, due to aged deterioration and metal fatigue, cracks originating from the unwelded portion of the root portion (deck propagating cracks that propagate through the deck plate and joint It is known that a bead propagation crack, which propagates in a penetrating direction through the weld bead of a part, occurs.

Conventionally, when a crack originating from the unwelded portion of the root portion as described above occurs at the joint portion of the side edge of the deck plate and the U-rib in the steel deck, the paving portion on the steel deck I was trying to repair it by removing it and reinforcing it with a backing plate.

In such conventional repair work, it is necessary to restrict traffic for the convenience of removing the paved portion on the steel deck. In recent years, in order to avoid this traffic restriction, for example, Welding methods have been proposed.
In this welding method, the crack is erased by setting the irradiation direction of the laser beam so as to match the propagation direction of the crack generated in the bead.

Japanese Patent No. 6092163

However, in the above-described conventional welding method for crack removal, even if the bead propagation crack can be eliminated by laser beam irradiation, it is assumed that the deck propagation crack that propagates in the direction of penetrating the deck plate cannot be removed. not. Therefore, it has been a conventional problem how to remove the deck propagating crack by laser light irradiation.

The present disclosure has been made to solve the above-described conventional problems. Repair laser welding method and repair that can remove not only bead propagation cracks but also deck propagation cracks by irradiating laser light without removing the pavement part on the steel deck when cracks occur The object is to provide a laser welding device for

A first aspect of the present disclosure is a non-removable part at a root portion between one material to be welded and the other material to be welded obliquely joined to the surface of the one material to be welded by fillet welding. A repair laser welding method for melting and erasing a crack starting from a welded portion by irradiating a laser beam, wherein the one welded material and the other welded material included in the unwelded portion of the root portion The laser beam is irradiated along the weld bead while aiming from the weld bead side of the root portion as the irradiation point of the laser beam at the point of contact with the material.
The position of the contact point between one material to be welded and the other material to be welded included in the unwelded portion of the root portion is specified by nondestructive inspection.

According to the repair laser welding method according to the present disclosure, for example, when a crack originating from an unwelded portion of the root portion is generated at the joint portion of the side edge of the deck plate and the U rib in the steel deck, It is possible to remove not only bead propagating cracks but also deck propagating cracks by irradiating laser light without removing the pavement portion on the floor slab, which is an extremely excellent effect.

1 is a perspective view of a steel deck installed in a steel deck box girder of a bridge showing a steel deck to which a repair laser welding method according to an embodiment of the present disclosure is applied; FIG. FIG. 2 is a partially enlarged front view showing an enlarged part of the steel deck of FIG. 1; BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a front explanatory view schematically explaining a repair laser welding device used in a repair laser welding method according to an embodiment of the present disclosure; FIG. 4 is an explanatory side view of the repair laser welding device of FIG. 3 ; FIG. 2 is a partially enlarged front view of a part corresponding to FIG. 2 showing a laser beam irradiation point of a repair laser welding method according to an embodiment of the present disclosure; 6 is a partially enlarged cross-sectional view showing the relationship between the laser beam irradiation point and the repair status in FIG. 5. FIG. FIG. 4 is a partially enlarged cross-sectional view showing the relationship between the number of laser light irradiation passes and the repair status in the repair laser welding method according to the embodiment of the present disclosure; FIG. 4 is a partially enlarged cross-sectional view showing the relationship between the number of laser light irradiation passes and the repair status in the repair laser welding method according to the embodiment of the present disclosure; FIG. 4 is a partially enlarged cross-sectional view showing the relationship between the number of laser light irradiation passes and the repair status in the repair laser welding method according to the embodiment of the present disclosure; FIG. 4 is a front explanatory view schematically explaining a repair laser welding device used in a repair laser welding method according to another embodiment of the present disclosure; FIG. 9 is an explanatory side view of the repair laser welding device of FIG. 8 ; FIG. 10 is a front explanatory view at the time of rail positioning, schematically illustrating a repair laser welding device used in a repair laser welding method according to still another embodiment of the present disclosure; FIG. 10 is a front explanatory view at the time of repair welding, schematically illustrating a repair laser welding apparatus used in a repair laser welding method according to still another embodiment of the present disclosure; FIG. 10B is an explanatory side view of the laser welding device for repair in FIG. 10A. FIG. 4 is a perspective explanatory view of a tab plate when tab plates are used at the start and end of laser welding in the laser welding method for repair according to the present disclosure; FIG. 4 is an external explanatory view of a weld bead showing an example of arrangement of tab plates when tab plates are used at the beginning and end of laser welding in the laser welding method for repair according to the present disclosure; FIG. 3 is a partially enlarged front view of a portion corresponding to FIG. 2 when tab plates are used at the start and end of laser welding in the laser welding method for repair according to the present disclosure; 12B is a perspective explanatory view showing another form example of the tab plate in FIG. 12A. FIG. 12B is a perspective explanatory view showing still another example of the form of the tab plate in FIG. 12A. FIG. FIG. 13B is a conceptual diagram in the case of performing laser welding for repair using the tab plate of FIG. 13B; FIG. 13B is a perspective explanatory view showing a preferred embodiment for use in place of the tab plate of FIG. 13B; FIG. 13C is a perspective explanatory view showing another preferred embodiment for use in place of the tab plate of FIG. 13B; FIG. 13C is a perspective explanatory view showing still another preferred embodiment for use in place of the tab plate of FIG. 13B; FIG. 15B is a side view of a state in which a backing plate is arranged when laser welding for repair is performed using the tab plate of FIG. 15A; FIG. 15B is a side view showing another arrangement example in which a backing plate is arranged when laser welding for repair is performed using the tab plate of FIG. 15A; FIG. 13C is a side view of a state in which a backing plate is arranged when laser welding for repair is performed using the tab plate of FIG. 13B; FIG. 2 is an enlarged cross-sectional explanatory view showing a repair procedure for a welded portion at a location intersecting with a lateral rib of a steel floor slab to which the repair laser welding method of the present disclosure is applied; FIG. 2 is an enlarged cross-sectional explanatory view showing a repair procedure for a welded portion at a location intersecting with a lateral rib of a steel floor slab to which the repair laser welding method of the present disclosure is applied;

Hereinafter, embodiments of the present disclosure will be described based on the drawings.
1 and 2 show a steel deck of a bridge steel deck box girder to which the repair laser welding method according to the present disclosure is applied, and FIGS. 3 and 4 show a repair according to an embodiment of the present disclosure. 1 shows a repair laser welding apparatus for use in a laser welding method for laser welding.

As shown in FIG. 1, a steel floor slab 103 that constitutes a steel floor slab box girder 100 together with a plurality of main girders 101 includes a deck plate (one material to be welded) 110 on which the pavement portion H of the bridge is placed, and this deck plate A plurality of U-ribs (the other material to be welded) 120 are arranged on the downward surface 112 on the side opposite to the pavement portion placing surface 111 of the 110 .

As shown in the enlarged circle of FIG. 1, grooves 122, 122 are formed at the ends of a pair of side edges 121, 121 of the U-rib 120 that obliquely contact the downward surface 112 of the deck plate 110. formed. The U-rib 120 is attached to the deck plate 110 by forming a weld bead B by fillet arc welding over the entire length between the grooves 122, 122 and the downward surface 112 of the deck plate 110. , thereby forming a closed cross-sectional structure together with the deck plate 110 .

At this time, as shown in FIG. 2, the root portion R at the joint portion between the deck plate 110 and the side edges 121, 121 of the U-rib 120 obliquely joined to the downward surface 112 of the deck plate is not welded. A portion S remains, and due to aged deterioration and metal fatigue, a crack starting from the unwelded portion S (deck growth progressing in a penetrating direction through the deck plate 110) occurs at the joint portion between the deck plate 110 and the U-rib 120. There is a possibility that the crack Cd and the bead propagation crack Cb) that propagates through the weld bead B at the joint portion in the direction of penetration may occur.

The repair laser welding apparatus 1 according to the present embodiment for removing the cracks Cd and Cb generated in the joint portion between the deck plate 110 and the U-rib 120 is, as schematically shown in FIGS. An oscillator 2, a laser head 4 for condensing laser light L supplied from the laser oscillator 2 through an optical fiber 3 and irradiating the repaired portion, and a head for moving the laser head 4 along the weld bead B. A drive mechanism 10 is provided.

The head driving mechanism 10 includes a rail base 11 fixed by magnets or the like to a base 123 between side edges 121 of a U-rib 120, and a carriage 12 on which the laser head 4 is mounted via an arm 7 and travels. equipped.

In this case, the trolley 12 is suspended from the rail base 11 by placing its wheels 12a, 12a on the rails 11a, 11a of the rail base 11. A motor (not shown) mounted on the trolley 12 It runs on the rails 11a, 11a, that is, runs along the weld bead B by the power from.

In addition, the repair laser welding apparatus 1 causes the irradiation point of the laser beam L emitted from the laser head 4 moving along the weld bead B by the head driving mechanism 10 to follow the joint portion of the deck plate 110 and the U rib 120. A copying mechanism 8 is provided.

The copying mechanism 8 includes two copying legs 8a and 8b having rollers 8c at their ends arranged on the laser head 4, a sub-arm 9a provided on the carriage 12, and a tension spring 9b. In this copying mechanism 8, the tension spring 9b is arranged between the sub-arm 9a and the arm 7, and the two copying legs 8a and 8b are attached to the downward surface 112 of the deck plate 110 and the side edge 121 of the U-rib 120, respectively. By pressing, the irradiation point of the laser beam L emitted from the laser head 4 is made to follow the joint portion of the deck plate 110 and the U-rib 120 .
Note that the tracing mechanism for tracing the irradiation point of the laser beam L to the joint portion between the deck plate 110 and the U-rib 120 is not limited to the configuration described above. For example, a sensor-based non-contact type copying mechanism may be used.

Furthermore, the repair laser welding apparatus 1 is provided with a weaving mechanism 6 built into the laser head 4, and is capable of weaving the laser beam L in the direction crossing the weld bead B within the range of the arrow in FIG. ing.

Furthermore, the repair laser welding device 1 has a shift mechanism. In this embodiment, an arm 7 supporting the laser head 4 also serves as a shift mechanism. Specifically, the arm 7 includes a support arm 7a provided on the carriage 12, an arm body 7c rotatably connected to the support arm 7a via a pin 7b, and an arm provided on the laser head 4 side. A moving arm 7d is fitted to the main body 7c so as to be movable in the axial direction (in the direction of the arrow in the drawing).

That is, in the arm 7 that also serves as a shift mechanism, the irradiation point of the laser beam L is shifted to the deck plate 110 and the U-rib 120 by moving the moving arm 7d with respect to the arm body 7c that is rotatably connected to the supporting arm 7a. can be shifted to the weld bead B side from the root portion R at the joint portion.

Reference numeral 5 in FIG. 3 denotes a controller, which controls the spot diameter of the laser beam L emitted from the laser head 4, the movement of the laser head 4 by the head drive mechanism 10, and the like. there is

When using the repair laser welding apparatus 1 configured in this way to remove the deck propagating crack Cd generated in the joint portion between the deck plate 110 and the U-rib 120 of the steel deck 103, first, the deck plate 110 and A non-destructive inspection such as an ultrasonic flaw detection test is performed on the joint portion of the U-rib 120, and as shown in FIG. The position of the contact point P between the side edge 121 of the U-rib 120 and the groove 122 is specified.

Next, by adjusting the angle of the arm body 7c of the arm 7 (shift mechanism) supporting the laser head 4 and moving the moving arm 7d with respect to the arm body 7c, the laser light L touches the contact point P. Therefore, the irradiation point of the laser light L is determined.

Then, the tension spring 9b of the copying mechanism 8 is set to press the two copying legs 8a and 8b against the downward surface 112 of the deck plate 110 and the side edge 121 of the U-rib 120, respectively.

Thereafter, the carriage 12 of the head driving mechanism 10 starts running according to a command from the control unit 5, and the laser head 4 starts moving while irradiating the contact point P with the laser light L having an appropriate spot diameter.
In this embodiment, the movement of the laser head 4 causes the laser beam L to pass (move) along the weld bead B once.

On the other hand, when removing the bead propagation crack Cb generated in the joint portion between the deck plate 110 and the U-rib 120 of the steel floor slab 103 using the repair laser welding apparatus 1 configured as described above, the laser beam L is applied to the weld bead. The laser head 4 is moved while irradiating toward B.

In the repair laser welding method according to this embodiment, the downward surface 112 of the deck plate 110 of the steel floor slab 103 included in the unwelded portion S in the root portion R and the groove 122 of the side edge 121 of the U rib 120 Since the contact point P is targeted as the irradiation point of the laser beam L, the unwelded portion S in the root portion R can be melted. As the unwelded portion S is melted, the deck-progressing crack Cd that has started from the unwelded portion S is also melted and removed.

Here, FIG. 6 is a partially enlarged sectional view showing the relationship between the laser beam irradiation point and the repair status, and shows the repair status when the laser beam L is passed along the weld bead B once.

In FIG. 5, if the irradiation point of the laser beam L is set inside the U rib 120 (less than 0 (-)) from the contact point P, the irradiation point of the laser beam L will be as shown in the partially enlarged cross-sectional view of FIG. The molten metal of the weld bead BL due to this flow into the inside of the U-rib 120 , and a hole is generated in the side edge 121 of the U-rib 120 .
At this time, even if the focus of the laser beam L is set to match the contact point P, the outer edge of the spot of the laser beam L is actually inside the U-rib 120 (region of less than 0 (-)). going to get in.
Therefore, it is desirable to set the irradiation point of the laser light L so that at least the outer edge of the spot of the laser light L touches the contact point P. By setting the irradiation point of the laser light L in this way, the irradiation of the laser light L It is possible to reliably prevent the molten metal from flowing to the inside of the U-rib 120 due to

On the other hand, if the irradiation point of the laser beam L is set too close to the weld bead B side (4 mm+) from the contact point P, as shown in the partially enlarged cross-sectional view of FIG. Since it does not reach the unwelded portion S, unwelded dust is generated.
Therefore, in this embodiment in which the laser beam L is passed once along the weld bead B, it is desirable to set the irradiation point of the laser beam L about 2 mm from the contact point P to the weld bead B side.

If the deck progressing crack Cd is small, as shown in the partially enlarged cross-sectional view of FIG. 7A, the laser beam L is passed along the weld bead B once to form the weld bead BL by irradiating the laser beam L. However, if the deck-growing crack Cd is large, as shown in the partially enlarged cross-sectional view of FIG. By shifting the irradiation point of the light L from the root portion R at the joint portion of the deck plate 110 and the U rib 120 to the weld bead B side and making multiple passes (by forming a plurality of weld beads BL by irradiating the laser light L ), the deck-growing crack Cd can be removed.

At this time, as shown in the partially enlarged cross-sectional view of FIG. 7C, the weaving mechanism 6 performs weaving with the laser beam L, and if a wide weld bead BLW is formed by the irradiation of the laser beam L, the risk of hot cracking is reduced. can do.

8 and 9 show a repair laser welding apparatus used in a repair laser welding method according to another embodiment of the present disclosure.

A repair laser welding apparatus 1A according to this embodiment, as schematically shown in FIGS. A laser head 4 for irradiating a spot and a head driving mechanism 10A for moving the laser head 4 along the weld bead B are provided.

In this embodiment, the head drive mechanism 10A comprises a rail 11A and a truck 12A running on the rail 11A, and the laser head 4 is mounted on the truck 12A via an arm 7A.

The repair laser welding apparatus 1A according to this embodiment also includes a rail arranging mechanism 20. The rail arranging mechanism 20 includes an L-shaped member 22 having magnets 21, 21 arranged at both ends thereof, and a head driving mechanism. It has a guide 23 arranged on the rail 11A of 10A.

The rail 11A of the head drive mechanism 10A is fixed to the base 123 of the U-rib 120 via one magnet 21 of the L-shaped member 22 of the rail arrangement mechanism 20. As shown in FIG. At this time, the other magnet 21 of the L-shaped member 22 is attracted to the downward surface 112 of the deck plate 110 (the surface of one of the materials to be welded where the other material to be welded is joined), and the guide 23 is moved to the U-rib 120. It abuts on the side edge 121 .

That is, the rail 11A of the head drive mechanism 10A is fixed with reference to both the downward surface 112 of the deck plate 110 and the side edge 121 of the U-rib 120, thereby moving along the weld bead B together with the carriage 12A. The irradiation point of the laser beam L emitted from the laser head 4 is the joint portion of the deck plate 110 and the U-rib 120 (the downward surface 112 of the deck plate 110 and the U-rib included in the unwelded portion S at the root portion R in FIG. 5). The contact point P) of the side edge 121 of 120 with the concave groove 122 is aimed.

When using the repair laser welding apparatus 1A according to this embodiment to remove the deck propagating crack Cd generated in the joint portion between the deck plate 110 and the U rib 120 of the steel deck 103, first, the deck plate 110 and the U rib 120 A non-destructive inspection such as an ultrasonic flaw detection test is performed on the joint portion of the rib 120, and as shown in FIG. The position of the contact point P between the side edge 121 of the rib 120 and the groove 122 is specified.

Next, the other magnet 21 of the L-shaped member 22 in the rail arrangement mechanism 20 is attracted to the downward surface 112 of the deck plate 110, and the guide 23 is brought into contact with the side edge 121 of the U-rib 120, that is, the deck plate 110 The rail 11A of the head driving mechanism 10A is fixed to the base 123 of the U-rib 120 via one of the magnets 21 of the L-shaped member 22, with both the downward surface 112 and the side edge 121 of the U-rib 120 as references.

As a result, the irradiation point of the laser beam L emitted from the laser head 4 moving together with the carriage 12A along the weld bead B is included in the unwelded portion S at the root portion R of the joint portion between the deck plate 110 and the U-rib 120. A contact point P is set.

After that, the truck 12A of the head driving mechanism 10A starts running, and the laser head 4 starts moving while irradiating the contact point P with the laser light L having an appropriate spot diameter.
Also in this embodiment, the movement of the laser head 4 causes the laser beam L to pass (move) along the weld bead B once.

On the other hand, when removing the bead propagating crack Cb generated in the joint portion between the deck plate 110 and the U-rib 120 of the steel floor slab 103 using the repair laser welding apparatus 1A configured as described above, the laser beam L is applied to the weld bead. The laser head 4 is moved while irradiating toward B.

Also in the repair laser welding method according to this embodiment, the groove 122 of the downward facing surface 112 of the deck plate 110 of the steel floor slab 103 and the side edge 121 of the U-rib 120 included in the unwelded portion S of the root portion R Since the contact point P with the root portion R is targeted as the irradiation point of the laser beam L, the unwelded portion S in the root portion R can be melted. As the unwelded portion S is melted, the deck-progressing crack Cd that has started from the unwelded portion S is also melted and removed.

10A, 10B, and 11 show a repair laser welding apparatus used in a repair laser welding method according to still another embodiment of the present disclosure.

As schematically shown in FIGS. 10A, 10B and 11, a repair laser welding apparatus 1B according to this embodiment condenses laser light L supplied from a laser oscillator (not shown) through an optical fiber 3. and a head drive mechanism 10B for moving the laser head 4 along the weld bead B.

This head drive mechanism 10B comprises a rail 20B and a carriage 22B on which the laser head 4 is mounted. In this case, the rail 20B has an angle iron shape and comprises a vertical plate 22Y and a horizontal plate 22X detachably connected to each other.

The vertical plate member 22Y of the rail 20B has a magnet 21 at each upper end at both ends in the longitudinal direction (horizontal direction in FIG. 11). It is fixed to (a surface of one material to be welded to which the other material to be welded is joined).
Further, grooves 22Ya extending in the vertical direction are formed at the lower end portions of both ends in the longitudinal direction of the vertical plate member 22Y.

In this embodiment, when the vertical plate member 22Y is fixed, as shown in FIG. 10A, positioning with respect to the U-rib 120 is achieved by interposing a guide 23B between it and the side edge 121 of the U-rib 120. I'm trying to
The guides 23B are interposed at appropriate positions in the longitudinal direction of the vertical plate member 22Y, such as at both ends, and are removed after the vertical plate member 22Y is fixed.

On the other hand, the horizontal plate member 22X of the rail 20B has a groove insertion projection 22Xa at its base end portion (left end portion in FIG. 10A) to be inserted into the groove 22Ya of the vertical plate member 22Y. A magnet 21 is provided at each tip (right end in FIG. 10A) at both ends.

The horizontal plate member 22X is fixed to the base 123 of the U-rib 120 via the magnet 21 with the groove insertion projection 22Xa inserted into the groove 22Ya of the vertical plate member 22Y. By adjusting the vertical position of the groove inserting projection 22Xa, positioning is performed with reference to the downward surface 112 of the deck plate 110 (the surface of one material to be welded to which the other material to be welded is joined). It's becoming

A long member 22Yb is arranged on the horizontal plate member 22X so as to be parallel to the vertical plate member 22Y. As shown in FIG. 10B, the carriage 22B of the head drive mechanism 10B travels on the travel path on the positioned horizontal plate member 22X while being guided by the vertically positioned vertical plate member 22Y and the elongate member 22Yb. It is designed to

That is, the irradiation point of the laser beam L emitted from the laser head 4 moving together with the carriage 22B along the weld bead B is the joint portion between the deck plate 110 and the U-rib 120 (the unwelded portion S at the root portion R in FIG. 5). The contact point P) between the downward facing surface 112 of the included deck plate 110 and the groove 122 of the side edge 121 of the U-rib 120 is aimed.

When using the repair laser welding apparatus 1B according to this embodiment to remove the deck propagating crack Cd generated in the joint portion between the deck plate 110 and the U rib 120 of the steel deck 103, first, the deck plate 110 and the U rib 120 A non-destructive inspection such as an ultrasonic flaw detection test is performed on the joint portion of the rib 120, and as shown in FIG. The position of the contact point P between the side edge 121 of the rib 120 and the groove 122 is specified.

Next, with the guide 23B interposed between the vertical plate member 22Y of the rail 20B and the side edge 121 of the U-rib 120, the downward surface 112 of the deck plate 110 (the other side of one member to be welded) is moved through the magnet 21. the surface to which the welded material is joined). That is, the vertical plate member 22Y of the rail 20B is fixed to the downward surface 112 of the deck plate 110 in a state in which the U-rib 120 is positioned.

Subsequently, the horizontal plate member 22X is fixed to the base 123 of the U-rib 120 via the magnet 21 with the groove insertion protrusion 22Xa of the horizontal plate member 22X inserted into the groove 22Ya of the vertical plate member 22Y. The vertical position of the groove insertion projection 22Xa with respect to the groove 22Ya of 22Y is adjusted, and positioning is performed with reference to the downward surface 112 of the deck plate 110 (the surface of one of the materials to be welded where the other material to be welded is joined). .

As a result, the traveling path of the carriage 22B that travels (along the weld bead B) while being guided by the vertical plate 22Y and the long member 22Yb is set on the horizontal plate 22X, and is irradiated from the laser head 4 on the carriage 22B. The irradiation point of the laser beam L is set at the contact point P included in the unwelded portion S at the root portion R of the joint portion between the deck plate 110 and the U-rib 120 .

Next, after removing the guide 23B from between the vertical plate member 22Y of the rail 20B and the side edge 121 of the U-rib 120, the carriage 22B of the head drive mechanism 10B starts running, and the contact point P is spotted as appropriate. The laser head 4 starts to move while irradiating the laser beam L of the diameter.
Also in this embodiment, the movement of the laser head 4 causes the laser beam L to pass (move) along the weld bead B once.

On the other hand, when removing the bead propagating crack Cb generated in the joint portion between the deck plate 110 and the U-rib 120 of the steel deck 103 using the repair laser welding apparatus 1B configured as described above, the laser beam L is applied to the weld bead. The laser head 4 is moved while irradiating toward B.

Also in the repair laser welding method according to this embodiment, the groove 122 of the downward facing surface 112 of the deck plate 110 of the steel floor slab 103 and the side edge 121 of the U-rib 120 included in the unwelded portion S of the root portion R Since the contact point P with the root portion R is targeted as the irradiation point of the laser beam L, the unwelded portion S in the root portion R can be melted. As the unwelded portion S is melted, the deck-progressing crack Cd that has started from the unwelded portion S is also melted and removed.

Further, in the repair laser welding apparatus 1B according to this embodiment, since the rail 20B is composed of the vertical plate member 22Y and the horizontal plate member 22X that are detachably connected to each other, when installing the rail 20B, the deck plate 110 The vertical plate member 22Y and the horizontal plate member 22X are positioned one by one with respect to the downward facing surface 112 and the U-rib 120.

In other words, each work can be performed without feeling the weight so much, and as a result, the workability is improved by the ease of positioning and installation of the rail 20B.

Furthermore, in the repair laser welding apparatus 1B according to this embodiment, since the running path of the carriage 22B is set on the horizontal plate member 22X of the rail 20B, the aiming operation of the laser beam L emitted from the laser head 4 can be performed. It will be easily done.

Here, in the repair laser welding method according to this embodiment, when removing by irradiating the laser beam L the bead propagation crack generated in the joint portion of the deck plate 110 and the U-rib 120, the rectangular parallelepiped shown in FIG. 12A As shown in FIGS. 12B and 12C, the tab plate T having the shape is placed at two points, the starting end and the terminal end of the repair welding portion in the weld bead B, and laser welding is performed. I am trying to remove T.

In this way, by arranging the tab plates T and T at the start and end of the repair weld location in the weld bead B and performing laser welding, the start and end of the repair weld location in the weld bead B with a high defect rate are sound. It is possible to ensure the reliability.

In this embodiment, as the tab plates arranged at the beginning and end of the repair welding location in the weld bead B, a wedge-shaped tab plate T1 shown in FIG. 13A and a wedge-shaped tab plate T1 shown in FIG. A trapezoidal tab plate T2 can be used.

For example, when laser welding for repair is performed using a tab plate T2 having a trapezoidal shape when viewed from the side, two tab plates T2 are placed on the surface of the steel material W so as to sandwich the crack Wa, as shown in FIG. , T2. Then, one of the obliquely cut side surfaces of the tab plates T2, T2 is brought into surface contact with the surface Wp of the steel material W, and the other side surfaces are inclined in a direction away from each other, and are joined by, for example, spot welding. .

Next, irradiation of laser light L is started to input heat from the side surface (so-called side surface) of the tab plate T2 on one side (the left side in the figure) held in surface contact with the surface Wp of the steel material W with an inclination.

In this case, since the laser beam L is set so as to be substantially perpendicular to the surface Wp of the steel material W and at a constant distance, the energy density is low in the vicinity of the edge surfaces of the tab plates T2, T2, so that they do not melt.

Therefore, instead of the tab plate T2 having a trapezoidal shape when viewed from the side, a tab plate T3 having a groove T3a along the welding direction as shown in FIG. A tab plate T4 having a notch T4a is adopted, or a tab plate T5 having a step T5a on the edge surface as shown in FIG. is desirable.

In this repair laser welding, when the tab plates T3 to T5 having the groove T3a, the notch T4a, and the step T5a are used, the base material is melted at the start and end of the laser beam irradiation. In order to avoid this, as shown in FIG. is preferably fitted into the notch Ta formed in the tab plate T3 (T4, T5). It is desirable to apply a backing plate U to the bottom.

17A and 17B show the scalloped portion of the lateral rib 130 arranged across the U-rib when performing the repair-laser welding on the joint portion of the deck plate 110 and the U-rib by the repairing laser-welding method according to this embodiment. The case where the laser beam L is applied to the portion located at 131 is shown.

In this way, when irradiating the portion of the lateral rib 130 located on the scalloped portion 131 with the laser beam L, first, as shown in FIG. (not shown) is temporarily stopped before the lateral rib 130, and in this state, the portion of the lateral rib 130 located at the scalloped portion 131 is irradiated with the laser beam L through the mirror 4a.

After that, as shown in FIG. 17B, the laser head is positioned on the right side of the horizontal rib 130 in the drawing, and a laser beam L is irradiated from the right side of the horizontal rib 130 to the scalloped portion 131 through the mirror 4a. That is, the welding is performed so as to wrap the portion located at the scalloped portion 131 .

At this time, in order to prevent an unwelded portion from occurring in the portion positioned at the scalloped portion 131, when the thickness of the lateral rib 130 is t and the distance of the scalloped portion 131 from the deck plate 110 is R, the laser beam L It is desirable that the irradiation angle θ with respect to the lateral rib 130 is at least 1/2 or more of the tangent angle α of tan α represented by t/R.

In each of the above-described embodiments, the repair laser welding method according to the present disclosure is used to join a deck plate constituting a steel deck plate of a bridge and a U-rib joined by fillet welding on the surface of the deck plate. Although the case where it is used for repairing a crack in a part has been described as an example, it is not limited to this.

Further, in each of the above-described embodiments, the cracks are removed only by the irradiation of the laser beam L. However, the present invention is not limited to this. Irradiation with the light L may be performed, and when the irradiation with the laser light L is performed while the solvent is being supplied in this way, the cracks can be reliably removed.

Furthermore, in each of the above-described embodiments, the cracks are removed only by the irradiation of the laser beam L, but other welding such as arc welding may also be used.

The configurations of the repair laser welding method and the repair laser welding apparatus according to the present disclosure are not limited to the above-described embodiments, and can be variously modified without departing from the spirit of the disclosure.

A first aspect of the present disclosure is a non-removable part at a root portion between one material to be welded and the other material to be welded obliquely joined to the surface of the one material to be welded by fillet welding. A repair laser welding method for melting and erasing a crack starting from a welded portion by irradiating a laser beam, wherein the one welded material and the other welded material included in the unwelded portion of the root portion The laser beam is irradiated along the weld bead while aiming from the weld bead side of the root portion as the irradiation point of the laser beam at the point of contact with the material.
The position of the contact point between one material to be welded and the other material to be welded included in the unwelded portion of the root portion is specified by nondestructive inspection.

In a second aspect of the present disclosure, the irradiation point of the laser beam is shifted from the contact point toward the weld bead, and the laser beam is passed multiple times along the weld bead.
At this time, the amount of shift of the irradiation point of the laser beam for one time is determined based on the spot diameter of the laser beam.

Furthermore, a third aspect of the present disclosure is configured to irradiate the laser beam along the weld bead while weaving the laser beam in a direction across the weld bead.

Furthermore, in the fourth aspect of the present disclosure, when aiming at a contact point between the one material to be welded and the other material to be welded included in the unwelded portion of the root portion as the irradiation point of the laser beam, The irradiation point is set so that at least the outer edge of the spot of the laser light touches the contact point.

Furthermore, a fifth aspect of the present disclosure is configured to irradiate the laser beam while supplying the solvent.

On the other hand, a sixth aspect of the present disclosure is a root portion between one of the materials to be welded and the other material to be welded that is obliquely joined to the surface of the one of the materials to be welded by fillet welding. A laser welding device for repair that melts and erases a crack that has occurred starting from an unwelded portion in the by irradiating a laser beam, comprising a laser oscillator, a laser head that irradiates the laser beam supplied from the laser oscillator, a head drive mechanism for moving the laser head along the weld bead of the root portion; It is configured to have a following mechanism for following the contact point between the one welding material and the other welding material included in the non-welded portion in the.

In addition, a seventh aspect of the present disclosure is a root portion between one of the materials to be welded and the other of the materials to be welded that is obliquely joined to the surface of the one of the materials to be welded by fillet welding. A laser welding device for repair that melts and erases a crack that has occurred starting from an unwelded portion in the by irradiating a laser beam, comprising a laser oscillator, a laser head that irradiates the laser beam supplied from the laser oscillator, A head driving mechanism for moving the laser head along the weld bead of the root portion is provided, the head driving mechanism includes a rail and a carriage on which the laser head is mounted and which travels on the rail, and the rail is , the irradiation points of the laser beam emitted from the laser head moving along the welding bead together with the carriage are positioned on the one material to be welded and the other material to be welded included in the unwelded portion of the root portion; In order to make the contact point, both the surface of the one weld material to which the other weld material is joined and the other weld material are fixed as a reference.

Further, according to an eighth aspect of the present disclosure, the rails of the head drive mechanism are formed in an angle steel shape including vertical plates and horizontal plates that are detachably coupled to each other, and the vertical plates of the rails are formed by the The horizontal plate member of the rail is positioned and fixed with reference to the other material to be welded, and the horizontal plate member of the rail is positioned relative to the vertical plate member fixed with reference to the other material to be welded. The horizontal plate member of the rail is positioned and fixed with reference to the surface to which the material to be welded is joined, and the horizontal plate member of the rail travels while the carriage of the head drive mechanism placed on the horizontal plate member is guided by the vertical plate member. It has a configuration formed as a road.

Furthermore, a ninth aspect of the present disclosure includes a weaving mechanism that weaves the laser beam in a direction across the weld bead.

Furthermore, in the tenth aspect of the present disclosure, the irradiation points of the laser light are the one material to be welded and the other material to be welded, in which at least the outer edge of the spot of the laser light is included in the unwelded portion of the root portion. It is configured to touch the contact point with the welding material.

In the repair laser welding method and repair laser welding apparatus of the present disclosure, a YAG laser or a semiconductor laser is generally used as the laser, but the laser is not limited to these.

1, 1A, 1B repair laser welding device 2 laser oscillator 4 laser head 6 weaving mechanism 7 arm (shift mechanism)
8 copy mechanisms 10, 10A, 10B head drive mechanisms 11A, 20B rails 12A, 22B cart 22X horizontal plate (rail)
22Y vertical plate (rail)
103 Steel deck 110 Deck plate (one material to be welded)
112 downward surface (surface to which the other welded material is joined in one welded material)
120 U-rib (other material to be welded)
121 U-rib side edge 122 Ra-shaped groove B Weld bead Cb Bead propagation crack Cd Deck propagation crack P Contact point R Root part S Unwelded part

Claims (10)

A crack that originates from an unwelded portion at the root between one material to be welded and the other material to be welded that is joined obliquely to the surface of the other material by fillet welding. A repair laser welding method for melting and erasing by irradiating laser light,
While aiming at the contact point between the one material to be welded and the other material to be welded included in the unwelded portion of the root part as the irradiation point of the laser beam from the weld bead side of the root part, A repair laser welding method for irradiating the laser beam along the surface. The repair laser welding method according to claim 1, wherein an irradiation point of the laser beam is shifted from the contact point toward the weld bead, and the laser beam is passed along the weld bead a plurality of times. The repair laser welding method according to claim 1 or 2, wherein the laser beam is irradiated along the weld bead while weaving the laser beam in a direction across the weld bead. When aiming at the contact point between the one material to be welded and the other material to be welded included in the unwelded portion of the root portion as the irradiation point of the laser beam, at least the outer edge of the spot of the laser beam is the contact point. The repair laser welding method according to any one of claims 1 to 3, wherein the irradiation point is set so as to touch. The repair laser welding method according to any one of claims 1 to 4, wherein the laser beam is irradiated while supplying the welding material. A crack that originates from an unwelded portion at the root between one material to be welded and the other material to be welded that is joined obliquely to the surface of the other material by fillet welding. A repair laser welding device that melts and erases by irradiating laser light,
a laser oscillator;
a laser head that emits laser light supplied from the laser oscillator;
a head driving mechanism for moving the laser head along the weld bead of the root;
The irradiation point of the laser beam emitted from the laser head moving along the weld bead by the head driving mechanism is set to the one welding material and the other welding material included in the unwelded portion of the root portion. A laser welding device for repair equipped with a tracing mechanism that traces the contact point with. A crack that originates from an unwelded portion at the root between one material to be welded and the other material to be welded that is joined obliquely to the surface of the other material by fillet welding. A repair laser welding device that melts and erases by irradiating laser light,
a laser oscillator;
a laser head that emits laser light supplied from the laser oscillator;
A head drive mechanism for moving the laser head along the weld bead of the root,
The head drive mechanism includes a rail and a truck mounted with the laser head and traveling on the rail, and the rail is irradiated with the laser beam from the laser head that moves together with the truck along the weld bead. In order to make the light irradiation point a contact point between the one weld material and the other weld material included in the unwelded portion of the root, the other weld material in the one weld material is A repair laser welding device fixed with reference to both the surface to be joined and the other welded material. the rail of the head drive mechanism has an angle steel shape with a vertical plate member and a horizontal plate member that are detachably coupled to each other;
The vertical plate material of the rail is positioned and fixed with reference to the other material to be welded,
The horizontal plate member of the rail is positioned with respect to the vertical plate member fixed with reference to the other to-be-welded material, with reference to the surface of the one to-be-welded material to which the other to-be-welded material is joined. fixed,
8. The laser welding for repair according to claim 7, wherein the horizontal plate member of the rail is formed as a travel path along which the carriage of the head drive mechanism mounted on the horizontal plate member travels while being guided by the vertical plate member. Device. The repair laser welding device according to any one of claims 6 to 8, further comprising a weaving mechanism for weaving the laser beam in a direction across the weld bead. The irradiation point of the laser beam is set so that at least the outer edge of the spot of the laser beam touches the contact point between the one material to be welded and the other material to be welded, which is included in the unwelded portion of the root portion. Repair laser welding equipment according to any one of claims 6 to 9.

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